Catherine Baskiotis

@conference{baskiotis_3924,

title = {Single-photon sensing of toxic Nitrogen dioxide and flammable Methane with silicon waveguides},

author = {Catherine Baskiotis and Abhishek Kumar Pandey and Deepak Jain},

url = {https://nanop2025.exordo.com/programme/presentation/364},

year  = {2025},

date = {2025-10-01},

booktitle = {NANOPHOTONICS 2025},

address = {Sorbonne Université, Paris, France},

abstract = {Single-photon operation in the Mid-IR 3-5?m wavelength range is particularly promising for the highly precise sensing of low-concentration gases [1] but remains currently unexplored due to the lack of detectors. Realizing ?sensing with undetected light? schemes is an identified technique for overcoming this lack [2-4]. With this technique, sensing in the Mid-IR is achieved while using telecom/Near-infrared/visible detectors [2-4]. Currently, this technique is founded on the generation of correlated photon pairs by Spontaneous Parametric Down Conversion in high-?2 materials [2-4], which present a lack of versatility and cost-effectiveness. Here, we present high-?3 silicon-on-insulator (SOI) waveguides enabling the generation of correlated photon pairs through Spontaneous Four-Wave Mixing, with the signal photon in the Mid-IR and the idler photon in the Telecom C-band. These waveguides are cheap and simple to fabricate.



We chose two hazardous gases: methane (CH4) and nitrogen dioxide (NO2) as target molecules and optimized two waveguides using the Finite Element Method through COMSOL software. For each waveguide, we ensured that the pump, signal, and idler wavelengths satisfied both energy conservation and phase-matching conditions by engineering the TE00 mode propagation constants. The waveguide 1 (w1) ensures the generation of a signal photon at 3265 nm inside the CH4 absorption band and the waveguide 2 (w2) targets a signal photon at 3461 nm inside the NO2 absorption band and outside the CH4 absorption band. For waveguide lengths of 2 cm, pulsed peak pump powers of 28.0 mW (w1) and 10.5 mW (w2), and pulse durations of 5 ps, we reached a maximum Pair Generation per pulse Probability (PGP) [5] of the order of 0.05, which is consistent with previous experimental works [6]. The PGP can be modified by simply increasing or decreasing the pump power. This approach can be extended to numerous other gases, by changing the waveguide dimensions to obtain different signal wavelengths in the mid-IR. Eventually, leveraging the SOI waveguides practical assets, it would be possible to construct waveguides arrays enabling species identification and precise quantification.



References:

[1] A. C. Cardoso et al., Opt. Continuum 3, 823-832 (2024)

[2] X. Y. Zou et al., Phys. Rev. Lett. 67, 318 (1991).

[3] Kalashnikov et al., Nat. Photonics, 10 (2), pp. 98-101, (2016).

[4] S. K. Lee et al., Phys. Rev. Applied 14, 014045, (2020).

[5] M. Barbier et al., Ph.D dissertation, Paris-Saclay Institut d'Optique Graduate School, Palaiseau, France (2014).

[6] Y. M. Sua et al., Sci Rep 7, 17494 (2017).},

note = {Oct 20-22, 2025},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}